Were Additional Treatments Affecting Pharmacokinetics Administered after Raltegravir Overdosing?: Authors' Reply.

The Authors Reply We would like to thank Fukuchi et al. for their interest in our recent case report published in Internal Medicine regarding a patient with HIV infection who overdosed on raltegravir (1). As they point out, the administration of laxatives and activated charcoal is commonly used in emergency rooms for patients who have overdosed on drugs. Activated charcoal administered for drug overdosing has the effect of reducing the quantity of drug absorbed from the gastrointestinal tract. Generally, the administration of activated charcoal within 1-2 hours after overdose may reduce the quantity of drug absorbed from the gastrointestinal tract (2,3), although the adsorbability of raltegravir onto activated charcoal remains unclear. Further studies are needed to clarify the effect of activated charcoal in patients who have overdosed on raltegravir. Whole-bowel irrigation with laxatives can facilitate the removal of select toxicants from the gastrointestinal tract in some patients (e.g., within 2 hours after overdosing or overdosing on sustained-release or enteric-coated drugs), but there is no convincing evidence from clinical studies that it improves the outcome of poisoned patients (4). Because the present patient was transferred to the hospital 6 hours after overdosing (1), we did not administer laxatives or activated charcoal. To our knowledge, the adverse effects of overdosing and excessive serum concentrations of raltegravir in the clinical setting have not been described previously, even though raltegrair can affect the neuropsychological, hepatic, gastrointestinal, and cardiovascular systems. Further case reports are needed to clarify the safety, adverse effects, and appropriate treatment of overdosing of raltegravir.

Author's disclosure of potential Conflicts of Interest (COI).

Toshio Naito: Honoraria, MSD.